Portable Python is not being developed anymore. At the moment there are several better and more up-to-date alternatives:
Python(x,y) is a free scientific and engineering development software for numerical computations, data analysis and data visualization based on Python programming language, Qt graphical user interfaces and Spyder interactive scientific development environment.
A free Python-distribution for Windows plattform, including prebuilt packages for Scientific Python.
Completely free enterprise-ready Python distribution for large-scale data processing, predictive analytics, and scientific computing
PythonAnywhere makes it easy to create and run Python programs in the cloud. You can write your programs in a web-based editor or just run a console session from any modern web browser.